Synthesis of novel diazaphosphinanes coumarin derivatives with promoted cytotoxic and anti-tyrosinase activities.

A series of α-aminocarbonitriles 2a-h, obtained by a condensation reaction of 4-hydroxycoumarin with malononitrile and a series of arylaldehydes, was reacted with Lawesson's reagent to give the diazaphosphinanes 3a-h and 3a'-h' as diastereoisomers. All the synthesized compounds were characterized by spectroscopic means such as NMR ((1)H, (13)C, (31)P) and MS. The synthesized compounds were evaluated for their cytotoxic activity in vitro against two tumor cell lines MCF-7 and HCT-116 and for their anti-tyrosinase effect. The results showed a moderate cytotoxic activity for most compounds and nearly all tested derivatives have been found considerable tyrosinase inhibitors.